The present invention relates to video waveform monitors, and more particularly to a bright video line select display for a video waveform monitor that enhances the visibility of a selected line of a video signal.
A common method of operation of a waveform monitor, such as the 1740A, 1750A and 1760 series of waveform monitors manufactured by Tektronix, Inc. of Wilsonville, Oreg., United States of America, is known as "line select" mode. In this mode only one or two video lines out of each video frame, i.e., out of 525 or 626 lines, is used for the display, resulting in a dim display on an economical cathode ray tube (CRT) display. The horizontal sweep rate is diminished by a factor of from 262 to 625, and the dimness is further worsened when the horizontal sweep time is divided in order to provide an expanded horizontal scale along the X-axis. The dimness of the display makes it difficult for an operator to observe the characteristics of the line selected for display, which difficulty is further compounded if the operator is observing the waveform monitor display from some distance. Thus the utility of this feature is limited by the display brightness.
What is desired is a method of providing a bright video line select display for a waveform monitor without corrupting the video signal that is displayed on a picture monitor.